James Marsden reveals he's not actually a Barry Manilow fan, saying his "famous actor friend" is the culprit: "He likes to go into other people's bios and add things."

Onstage during the Napa Valley Film Festival on Nov. 9, in Yountville, Calif., Billy Bush asked James Marsden what roles the actor had turned down -- Marsden claimed he wasn't in a position to do so -- and why he's such a big Barry Manilow fan.

Marsden laughed and said he's constantly asked this about the singer but that it's just not true. The Access Hollywood host protested that he got it from a presumably reliable source: the actor's IMDb bio.

So it must be correct, right? Not so much. Explains Marsden, "I have a famous actor friend of mine -- I won't tell you who he is -- but he likes to go into other people's bios and add things."

A spokesperson for IMDb acknowledges the ease with which a prankster can wreak havoc: "We make it easy for users and professionals to update much of our content, which is why we have an 'edit page.'The data that is submitted goes through a series of consistency checks before it goes live. Given the sheer volume of the information, occasional mistakes are inevitable, and, when reported, they are promptly fixed. We always welcome corrections."